I think most of the people working on mesh related geometry are doing it part-time and building these libraries is part of the learning experience. Asking questions is important, since it is the only way to gain insight. If you have more questions about Meshes, I'd be happy to help on the github bug tracker.
My senior thesis is on Polyhedra, and I thought it would be easy since I have been working with mesh types for over a year. It turned out I was wrong, and the needs of the application revealed a whole set of types (and more importantly relations between them) that are very important for combinatorial geometry. Stretching the application of libraries is really important, and I am sure in time you will be contributing back if you stick with it! On Mon, Nov 23, 2015 at 7:31 AM, kleinsplash <[email protected]> wrote: > Nope. I have obj files. Your hypothesis is correct. I have attached one of > them. Your script works just fine (is there an easy way to save this > image?). > > As a side note: I do collect point clouds using V-REP, and I can generate > pointclouds (pcd) using pcl - but I want to work with the obj mesh files > because the clouds are too sparse. > > I probably could have explained myself better, point taken. I will aim to > try harder next time, I feel horrid when I am asking basic questions and on > top of that writing an essay. > > The only other person I know who uses the term interwebz is Richard on > Fast and Loud - I am an avid supporter. > > On Monday, 23 November 2015 13:41:40 UTC+2, Simon Danisch wrote: >> >> I'm not sure what you mean by virtual objects. Obj is in the context of >> 3D objects is usually the wavefront >> <https://en.wikipedia.org/wiki/Wavefront_.obj_file> format. >> If you have an object database with *.obj's in it, the probability is >> very high, that you don't have pointclouds whatsoever. >> You can try this, to confirm my hypothesis: >> >> using GLVisualize, FileIO >> obj = load("file.obj") >> w,r = glscreen() >> view(visualize(obj)) >> r() >> >> Or just download any obj viewer from the interwebzz and look at that >> thing. >> If you have nice smooth surfaces, you're getting it all wrong with the >> pointclouds and ray tracing. >> I could give you some hacky way of extracting depth images with >> GLVisualize, if that's what you're after. >> In that case, just try the example above and if that works, open an issue >> at GLVisualize that you want depth images. Then we can take it from there. >> >> >> If by any chance you DO have pointclouds stored in an obj file, things >> are more complicated since you then need to approximate the surface of that >> cloud. >> Still, raytracing wouldn't be your friend ;) If you have infinitely small >> points, there is no magic that lets a ray hit these points any better then >> some other visualization algorithm. >> Even if it's really dense, you still have infinitely small points. You >> can treat the points as particles, to give them some "body" that you can >> see, but then it's not really a surface anymore. >> >> Just google for pointcloud surface approximation and see where that gets >> you. >> >> I'm guessing here, that you have some sensor that outputs depth images >> and you want to recognize objects in these depth images. >> To train your depth image classifier, you need depth images from a lot of >> perspectives from a lot of random 3D objects, which is why you searched for >> a 3D object database, which got you to the obj files of random 3D objects. >> >> It'd have been a lot easier, if you just stated this in your problem >> description, probably even with links to the obj database. >> >> Best, >> Simon >> >> Am Freitag, 20. November 2015 16:18:46 UTC+1 schrieb kleinsplash: >>> >>> I was wondering if someone could help me out with a decision/offer an >>> opinion: >>> >>> I need a ray tracer that deals with complex geometry (a fast ray tracer >>> that can create 1000's of point clouds in minimal time) >>> Python has methods: http://pyopengl.sourceforge.net/ that I could get >>> to grips with. But I want to stick with Julia. >>> >>> I have found these resources: >>> https://github.com/JuliaGL/ModernGL.jl - not sure if this has a ray >>> tracing option >>> http://www.cs.columbia.edu/~keenan/Projects/QuaternionJulia/ - looks >>> crazy complicated >>> >>> https://github.com/JuliaLang/julia/blob/master/test/perf/kernel/raytracer.jl >>> - looks like only handles simple geometry >>> >>> Could someone point me in the right direction? >>> >>> >>> >>
